Coaxial cable stripper



1954 w. D. IMMAN ETAL COAXIAL CABLE STRIPPER Filed April 8, 1952 IN V ENTORS.

[1/4/11 0 Mid/HIV United States Patent Ofifice 2,695,537 Patented Nov.30, 1954 COAXIA-L CABLE STRIPPER William D. Imman, (Iarmichael, andMyron E. J. Fuller, Sacramento, Calif.

Application April 8, 1952, Serial No. 281,256

2 Claims. (Cl. 819.5)

(Granted under Title 35, U. S. Code (1952), see. 266) The inventiondescribed herein may be manufactured and used by or for the Governmentfor governmental purposes without payment to us of any royalty thereon.

This invention relates to a cable stripper especially adapted for usewith coaxial cable, but which may also be used with other kinds.

One object of the invention is to provide a tool capable of producing atone operation, a cable end having two stripped shoulders, one at thejunction of the projecting bare wire with the rubber jacket and tubularconductor and the second one at the junction of the tubular conductorwith the outer covering of the cable, which may be covered with metallicbraid.

Another object is to produce a tool of the above character, the toolbeing of small dimensions and being readily portable in an electricianstool box.

Another object is to produce a tool of the above nature in which theamount of wire to be uncovered by the cut is readily adjustable, butwhich will stay constant for many cuts until purposely changed.

A still further object of this invention is to provide a cable stripperwhich has a limiting means and cutter means located at predeterminedpositions so as to remove in one operation a predetermined amount ofinsulation from the cable to be stripped.

Referring now to the drawings, Fig. l is a side elevation of thestripped cable end to be produced by the tool, the original dimensionsbeing indicated by dashed lines and the knife positions by dotted lines.

Fig. 2 is a perspective view of the tool, together with a length ofcable which is to be worked upon. The cable holding means (a vise andsemi-cylindrical block therein) is shown in dashed line.

Fig. 3 is a side elevation of the tool and cable shown in Fig. 2.

Fig. 4 is a vertical section taken on the line 4-4 of Fig. 3.

Referring now more particularly to Figs. 2 and 3, 1% is a cylindricalhollow body, the forward end of which is partially cut away to form ashouldered portion 11. The portion 11 is adapted to act as a rest forthe cable 12 which is to be stripped. The free end of the cable 12 isfitted into the body until it meets a cylindrical stop 13 (see Fig. 3)which is slidable with a fairly close fit in the bore 14 of the body 10.A screw 15, which has a large knurled head 16, is threadedly engaged inthe stop 13 and is adapted to engage the interior wall of the body 10 atits highest points. The screw 15 projects through a slot 17 which ispreferably slightly shorter than the length of the stop 13. The knurledhead 16 is preferably at such a distance from the bottom of the body 10so that whenthe screw engages the interior wall of the body the knurledhead 16 can act as a support for the entire tool on a bench surface (notshown), but the relation of which. to head 16 and to a vise 18, mayreadily be adjusted. The vise 18 is provided with a pair of matedsemi-cylindrical blocks 19a and 1917, which are hollowed justsufiiciently to hold the cable 12 tightly between them when the vise 18is tightened, without crushing the cable.

Attached to the top of the cylindrical body 10 at the rear thereof, byscrew 20, there is a long spring 21 on the extreme outer end of which isa short triangular knife 22 and further in from the end is a longerknife 23 of the same kind. The possible depth of insertion of the knife22 should correspond to the height of the shoulder 24. This shoulder isshown in Fig. 1. The length of possible insertion of the knife 23shouldbe that of the height of the shoulder 25, shown in Fig. 1, plusthe height of the shoulder 24. For other kinds of cable requiringdifferent dimensions of cuts, the entire knife assembly, i. e. 21, 22,23 may readily be removed from the body 10 by loosening the screws 20,and a different knife assembly of different dimensions affixed to thebody by again tightening these screws.

As will be seen in Figs. 2 and 3, the knife assembly may be subjected topressure from a pad 26 to which is loosely attached the screw 27, whichis: also provided with an upwardly projecting. knurled head 28. Thescrew 27 threadedly engages the boss 29, which is preferably integralwith an oblong collar 30, the lower end 31 of vhich is curved to fit thebody 10. A hole 32 through .vhich the knife 23 may pass as it is forcedinto the cable 12 under the urging of the screw 27, is provided in thebody 10 at the top thereof just behind the shoulder 11. The short cutter22 will enter the cable :in front of the shoulder 11, while the longcutter 23 will enter the cable a predetermined fixed distance behind theshort cutter 22. Therefore no time will be lost in fixing the distancebetween the cuts since this will be predetermined once and for all whenthe knives are afiixed to the spring 21, preferably by the process ofsilver-soldering.

Referring to Fig. 4, the positions of the knives 22 and 23 may bereadily seen. The knife 23 extends through the embedded hollow conductor33 of the cable 12 while the shorter one 22 extends only to the surfaceof the hollow conductor 33. The cutter 23 extends all the way to theinner wire 34 but only to the surface thereof; the conductor 22 willextend only to the top surface of the conductor 33 when the screw 27 istightened down so fully that that part of the spring 21 between the twocutters rests on the surface of the body 10.

After the cutting knives 22 and 23 have been thus forced into-the cableunder the action of the screw 27 through manual rotation of its head 28,the tool is rotated m nually by means of a T handle 35 whichis fittedthrough the body 10 at right angles thereto near that end of the bodywhich is furthest from the shoulder 11. The entire assembly is rotatedaround the cable about three times, more or less, while the cable isheld motionless in the vise 18 and blocks 19a and 19b. Two clean cutswill be produced under these conditions. The tool is no removed from thecable by grasping the T ha dle 35 and pulling the entire tool away fromthe cable end. This action strips the two layers of covering and willleave the cable in condition shown in Fig. 1. After the screw 27 isloosened to allow the spring 21 to lift the knives. the severed ends ofthe cable insulation can and sho ld be shaken out of the toolpreparatory to the next cut. The stop 13 may, of course, be set toobtain v rious lengths of bare central conductor wire by sliding it andthe associated screw 15 forward or backward in the slot 17 and tihtening the screw at the selected position.

We claim as our invention:

1. In a device for stripping cable ends to make a pluralitv of shouldersthereon, a hollow cylindrical bodv, adjustable stop means within saidbody, a spring strip attached to said body near one end thereof. apluralitv of spaced triangular knives of ditferent lengths attached atan angle to the non-attached end of said spring strip, manually-actuablepressure-applying means mounted substantially on the other end of saidbody engaging said spring strip to exert pressure downwardly on the endof said spring strip from a point above said knives to embed said knivesin said cable jackets and lever means mounted substantially at that endof said body furthest from said knives whereby all of said foregoingelements mav be r tated with said cable end as an axis to separateportions of said iackets from the conductor portions of said cable.

2. In a device for strippin the end of a coaxial cable to form aplurality of shoulders thereon, a hollow cylindrical body having apartially cutaway portion proiecting lonqitudinallv therefrom for thesupport of a cable end. a m nuallv adiustable cvlindrical stop for thecable end within said cylindrical body, a spring strip mounted by oneend thereof on said body to project normally at a low angle therefrom. apair of triangular knives of different lengths attached at a spacedinterval to the nonattached end of said spring strip, said body beingprovided with an opening for the rearward one of said knives to enterthe body and penetrate the cable, the outer knife extending into saidpartially cutaway portion, means for exerting downward pressure on theend of said strip and said knives, said means comprising a strapattached to said body and arising therefrom to form a substantiallyrectangular structure, a 'manually rotatable screw threadedly mounted inthe top of said structure and engaging the top of said strip through apad, and a handle mounted crosswise of the body on that end to which thestrip is attached whereby the entire assembly of the foregoing parts maybe manually rotated with the cable as an axis to cut a length of tubularconductor and at least two lengths of associated insulation from saidcable to form two spaced shoulders thereon.

References Cited in the file of this patent Number Number UNITED STATESPATENTS Name Date Williams Dec. 22, 1925 Wachstein Aug. 10, 1937 EdwardsJune 14, 1938 Hufi Dec. 20, 1938 FOREIGN PATENTS Country Date DenmarkMar. 16, 1908

